JP2005042819A - Electromagnetic proportional pressure control valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic proportional pressure control valve capable of controlling the fluid pressure in a control passage in a predetermined control mode without enlarging an electromagnetic apparatus even when the diameter of the control passage is increased. <P>SOLUTION: In the electromagnetic proportional pressure control valve, a control passage 4 with pressurized fluid flowing therein and a discharge passage to allow working fluid to flow to the low-pressure side are communicated with a valve hole 2 of a valve body 1, a valve seat 7 is formed between a control passage communication part and a discharge passage communication part of the valve hole 2, and a valve element 12 which is seated on or separated from the valve seat 7 is movably accommodated in the valve hole 2. The spring force of a pressure regulation spring 13 is applied to the valve element 12 in the seating direction, and the fluid pressure of the control passage 4 is applied against the spring force of the pressure regulation spring 13 in the separating direction. In the control valve, a piston 14 to control the spring force of the pressure regulation spring 13 is movably accommodated in the valve hole 2, the pilot pressure corresponding to the working force of an electromagnetic apparatus 21 of a pilot valve 18 is applied to the piston 14, the piston 14 is moved according to the pilot pressure to control the spring force of the pressure regulation spring 13. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention sets the fluid pressure in the control passage to the maximum pressure when the acting force of the electromagnetic device is zero (when the energization current to the electromagnetic device is zero), and increases the acting force of the electromagnetic device (the electromagnetic device). The present invention relates to an electromagnetic proportional pressure control valve that can be set to a pressure that decreases the fluid pressure in the control passage in accordance with an increase in the energizing current to the control passage.

This type of electromagnetic proportional pressure control valve is disclosed in, for example, Patent Document 1 below, and is a valve body connected to one end side of a movable iron core in a valve seat formed between a control passage and a discharge passage of a valve body. The valve body is urged in the seating direction to the valve seat by the spring force of the pressure adjusting spring. The electromagnetic core of the electromagnetic device in which the movable iron core is attracted to the fixed iron core by energizing the coil of the electromagnetic device including the fixed iron core, the movable iron core, the coil, etc., and the valve element is in the seating direction against the spring force of the pressure regulating spring. An acting force is generated in the movable iron core, and the acting force of the electromagnetic device generated in the movable iron core is increased in accordance with an increase in the energization current to the coil. For this reason, when the coil is not energized, the electromagnetic force of the electromagnetic device is not generated in the movable iron core, and only the spring force of the pressure adjusting spring is applied to the valve body, and the fluid pressure in the control passage is set to the maximum pressure. Is possible. In addition, when the coil is energized, the acting force of the electromagnetic device increases according to the increase of the energizing current, and a force corresponding to the difference between the spring force of the pressure regulating spring and the acting force of the electromagnetic device is applied to the valve body, It is possible to set the pressure in the control passage to a pressure that decreases as the energization current increases.
Japanese Utility Model Publication No. 3-614

  However, in the conventional electromagnetic proportional pressure control valve described above, since the control passage is directly controlled to open and close by the seating / separation of the valve body connected to one end side of the movable iron core, the diameter of the control passage becomes large. As a result, the valve body has become large, and the movable iron core connecting the valve bodies has become large and the electromagnetic device has to be enlarged.

  The present invention provides an electromagnetic proportional pressure control valve capable of controlling the fluid pressure in a control passage in an intended control form without increasing the size of the electromagnetic device even when the diameter of the control passage becomes large. The electromagnetic proportional pressure control valve has a control passage through which the pressure fluid flows and a discharge passage through which the working fluid flows to the low pressure side at a required axial interval in the valve hole of the valve body. A valve seat is formed between the control passage communicating portion and the discharge passage communicating portion of the valve hole, and the valve body seated and separated from the valve seat is movably accommodated in the valve hole. In this valve body, the spring force of the pressure adjusting spring accommodated in the valve hole acts in the seating direction, and the fluid pressure in the control passage is separated against the spring force of the pressure adjusting spring. A piston acting in the seat direction and increasing / decreasing the spring force of the pressure regulating spring moves to the valve hole. A pilot pressure corresponding to the acting force of the electromagnetic device provided in the pilot valve acts on this piston, and the piston moves according to the pilot pressure, and the spring force of the pressure regulating spring is It was configured to increase or decrease.

  In this case, the electromagnetic device is an electromagnetic device in which the acting force by which the movable iron core is attracted to the fixed iron core is increased in accordance with an increase in the energization current to the coil, and the pilot valve is an increase in the acting force of the electromagnetic device. A pilot valve body and a pilot valve seat that increase the pilot pressure in response to the pilot pressure, and the pilot pressure acts on the piston in a direction to reduce the spring force of the pressure regulating spring, and the valve hole It is also possible to configure so that the spring force of the housed return spring acts against the pilot pressure.

  In the electromagnetic proportional pressure control valve of the present invention, when the acting force of the electromagnetic device is zero (when the energization current to the electromagnetic device is zero), the piston is moved to the initial position by the pilot pressure applied to the piston from the pilot valve. In this case, the spring force of the pressure adjusting spring is not reduced and is maintained at the initial set value. Therefore, the fluid pressure in the control passage is set to a maximum pressure corresponding to the spring force of the pressure regulating spring maintained at the initial set value. Further, when the acting force of the electromagnetic device increases (when the energization current to the electromagnetic device increases), the piston moves according to the pilot pressure applied to the piston from the pilot valve, and this piston The spring force of the pressure regulating spring is reduced in accordance with the movement. Therefore, the fluid pressure in the control passage is set to a pressure corresponding to the spring force of the pressure regulating spring that decreases as the energization current increases.

  By the way, in the electromagnetic proportional pressure control valve of the present invention, the valve body is pressed against the spring force of the pressure adjusting spring by the pressing force based on the fluid pressure in the control passage, thereby opening the pressure passage in the control passage. Flows to the low pressure side of the discharge passage without passing through a pilot valve equipped with an electromagnetic device. For this reason, even when the control passage, the valve hole, the valve body, the discharge passage and the like are enlarged, it is not necessary to enlarge the pilot valve provided with the electromagnetic device. Therefore, it is possible to control the fluid pressure in the control passage in the above-described intended control mode while maintaining the downsizing of the pilot valve including the electromagnetic device.

  Further, in the implementation of the present invention, the electromagnetic device is an electromagnetic device in which an acting force of the movable iron core attracted to the fixed iron core is increased in accordance with an increase in an energization current to the coil, and the pilot valve is a member of the electromagnetic device. A pilot valve body and a pilot valve seat that increase the pilot pressure in response to an increase in acting force are provided, and the pilot pressure acts on the piston in a direction that reduces the spring force of the pressure regulating spring, When the spring force of the return spring accommodated in the valve hole is configured to act against the pilot pressure, a general-purpose electromagnetic device in which the pilot pressure increases with an increase in the energization current to the coil is used. Thus, the electromagnetic proportional pressure control valve can be configured.

  FIG. 1 shows an embodiment of an electromagnetic proportional pressure control valve according to the present invention. A valve body 1 of this electromagnetic proportional pressure control valve includes a valve seat member 6, a valve body 12, a pressure regulating spring 13, and a piston 14. A multistage valve hole 2 for accommodating the return spring 16 and the like is provided in the axial direction. The valve hole 2 has a medium diameter portion 2A from one side in the axial direction, a small diameter portion 2B having a smaller diameter than the medium diameter portion 2A, a medium diameter portion 2C substantially the same diameter as the medium diameter portion 2A, and a large diameter larger than the medium diameter portion 2C. The stop portion 2E is formed at the connecting step portion of the medium diameter portion 2C and the large diameter portion 2D. The valve hole 2 is connected to and communicated with the control hole 4 through which the pressure fluid flows from the pressure source P through the joint member 3 and connected to the intermediate diameter portion 2A in the axial direction from the communicating portion of the control path 4. A discharge passage 5 connected to a tank T as a low pressure side is connected to and communicated with the medium diameter portion 2C formed at a required interval.

  In addition, a valve seat member 6 is fitted and fixed in a small diameter portion 2B between the communicating portion of the control passage 4 and the communicating portion of the discharge passage 5 in the valve hole 2, and the valve seat member 6 has a valve seat. A seat 7 is formed, and a stepped through hole 8 connected to the valve seat 7 is provided in the axial direction. Further, a throttle member 10 having a throttle hole 9 is fixedly provided at the tip of the valve seat member 6, that is, at the tip of the small-diameter portion facing the control passage 4 communicating portion of the through hole 8. In addition, a passage 11 that opens to the outer peripheral surface of the valve seat member 6 so as to communicate with the distal end of the large-diameter portion of the through hole 8 is formed in the middle portion of the valve seat member 6 in an oblique radial direction.

  The valve body 12 is a poppet-like valve body that sits on and separates from the valve seat 7 and is accommodated in the middle diameter portion 2C of the valve hole 2 so as to be movable in the axial direction. 6 are inserted into the through holes 8 so as to be slidable in the axial direction. The valve body 12 is pressed in the separation direction against the spring force of the pressure adjusting spring 13 by a pressing force based on the fluid pressure of the control passage 4 acting through the throttle hole 9 on the head. The pressure regulating spring 13 is interposed between the valve body 12 and the piston 14 at the middle diameter portion 2C of the valve hole 2, and presses the valve body 12 in the seating direction by the spring force.

  The piston 14 is for increasing or decreasing the spring force of the pressure regulating spring 13, and is constituted by connecting a medium diameter part 14A and a large diameter part 14B larger in diameter than the medium diameter part 14A. The portion 14A is accommodated in the middle diameter portion 2C of the valve hole 2 and the large diameter portion 14B is movably accommodated in the large diameter portion 2D of the valve hole 2. Further, the piston 14 is provided with a shoulder portion 14C formed at a connecting step portion of the medium diameter portion 14A and the large diameter portion 14B so as to be able to contact with and separate from the stopper portion 2E of the valve hole 2. An annular pilot chamber 15 is defined in the end portion on the medium diameter portion 2C side of the large diameter portion 2D.

  The pilot chamber 15 is a chamber for introducing a pilot pressure applied from the pilot valve 18, and the pilot pressure introduced into the pilot chamber 15 is in a direction away from the valve body 12 to the piston 14, that is, the pressure regulating spring 13. Acting in the direction of decreasing the spring force. The return spring 16 is a spring in which the spring force is larger than the spring force of the pressure regulating spring 13 in the mounted state, and is housed in the large-diameter portion 2D of the valve hole 2, and the other side in the axial direction of the piston 14 and the valve hole 2 The piston 14 is pressed in the approaching direction to the valve body 12, that is, in the direction of increasing the spring force of the pressure regulating spring 13.

  With this configuration, the piston 14 sets the spring force of the pressure adjusting spring 13 to the initial maximum value unless the sum of the pressing force based on the pilot pressure and the spring force of the pressure adjusting spring 13 exceeds the spring force of the return spring 16. The shoulder 14C comes into contact with the stop portion 2E of the valve hole 2 as close as possible to the valve body 12, and the spring force of the pressure regulating spring 13 is reduced so that the spring force of the pressure regulating spring 13 is reduced as the pilot pressure increases. It is provided so as to be movable in a direction away from the valve body 12 to an equilibrium position between the pressing force based on the spring force and pilot pressure and the spring force of the return spring 16.

  The pilot valve 18 is a relief valve capable of adjusting the pilot pressure acting on the piston 14, and the pilot valve main body 19 is mounted above the valve main body 1. A multistage pilot valve hole 20 is provided in the pilot valve main body 19 in the axial direction. The pilot valve hole 20 has a large diameter portion 20A from one side in the axial direction, a small diameter portion 20B having a smaller diameter than the large diameter portion 20A, a medium diameter portion 20C having a diameter larger than the small diameter portion 20B and smaller than the large diameter portion 20A. An electromagnetic device 21 is mounted on the pilot valve main body 19 so as to close the large-diameter portion 20A side opening. A pilot control passage 22 through which pilot pressure fluid from the pilot pressure source P1 flows is connected to the middle diameter portion 20C of the valve hole 20 via a pressure compensating flow rate adjusting valve 23.

  The flow rate adjusting valve with pressure compensation 23 introduces a predetermined flow rate of pilot pressure fluid into the middle diameter portion 20C by controlling the differential pressure across the built-in throttle substantially constant regardless of the pressure fluctuation on the pilot pressure source P1 side. Yes. A pilot valve seat member 24 is fitted and fixed to the small diameter portion 20B of the pilot valve hole 20. A pilot valve seat 25 is formed on the pilot valve seat member 24. A continuous stepped through hole 26 is provided in the axial direction, and the intermediate diameter portion 20 </ b> C and the large diameter portion 20 </ b> A communicate with each other via the pilot valve seat 25. The pilot valve hole 20 has an intermediate diameter portion 20C communicating with the pilot chamber 15 via pilot passages 27 and 28, and a large diameter portion 20A of the pilot valve hole 20 is connected to the valve hole 2 via pilot passages 29 and 30. It communicates with the medium diameter portion 2C.

  The electromagnetic device 21 includes a coil 32, a fixed iron core 33, and a movable iron core 34 in a case 31 serving as a magnetic path. The movable iron core 34 is provided so as to be movable in the axial direction so as to face the fixed iron core 33. 31 is attached to the pilot valve main body 19 on the fixed iron core 33 side, and a lid member 35 is attached to the movable iron core 34 side of the case 31 to close the inside. Further, the movable iron core 34 is integrally provided with a rod-shaped member 36 projecting from both ends in the axial direction at the center in the radial direction, and both ends of the projecting rod-shaped member 36 are fixed to the fixed core 33, via bearings 37, 38. It is supported by the lid member 35 and provided concentrically with the pilot valve seat 25.

  A pilot valve body 39 is provided concentrically and integrally at the end of the rod-shaped member 36 on the pilot valve seat 25 side. The pilot valve body 39 is a poppet-like valve body that is seated on and separated from the pilot valve seat 25, is movably accommodated in the large-diameter portion 20 </ b> A of the pilot valve hole 20, and acts on the head through the through hole 26. The pilot valve hole 20 is pressed in the direction away from the pilot valve seat 25 by a pressing force based on the pressure of the pilot pressure fluid introduced into the medium diameter portion 20C of the pilot valve hole 20.

  With this configuration, in the electromagnetic device 21, the acting force by which the movable iron core 34 is attracted to the fixed iron core 33 increases as the energization current to the coil 32 increases. Further, in the pilot valve 18, the stationary iron core 33 is inserted so as to increase the pilot pressure in response to an increase in the acting force of the electromagnetic device 21, and the tip of the pilot valve body 39 is connected to the rod-like member 36 of the movable iron core 34. The acting force of the device 21 is applied to the pilot valve body 39 in the seating direction on the pilot valve seat 25.

  In the electromagnetic proportional pressure control valve of this embodiment configured as described above, when the energization current to the electromagnetic device 21 of the pilot valve 18 is zero, the operation of the electromagnetic device 21 that presses the pilot valve body 39 in the seating direction. No force is generated, and the pilot valve body 39 flows through the pilot control passage 22 from the pilot pressure source P1 and is pressed by the pressing force based on the pressure of the pilot pressure fluid introduced into the intermediate diameter portion 20C of the pilot valve hole 20 and pilot. Separate from the valve seat 25. Therefore, the pilot pressure fluid flows from the pilot valve seat 25 through the large diameter portion 20A of the pilot valve hole 20, the pilot passages 29 and 30, the middle diameter portion 2C of the valve hole 2 and the discharge passage 5, and is discharged to the tank T. .

  At this time, the pilot pressure introduced into the pilot chamber 15 from the intermediate diameter portion 20C of the pilot valve hole 20 via the pilot passages 27 and 28 and acting on the piston 14 is the lowest. For this reason, the piston 14 does not move against the spring force of the return spring 16, but is pressed by the spring force of the return spring 16 as shown in FIG. It is closest to the body 12, and the spring force of the pressure regulating spring 13 is not reduced but is maintained at the initial set value (maximum value).

  Further, at this time, the valve body 12 is pressed by the spring force of the pressure regulating spring 13 maintained at the initial set value (maximum value) and is seated on the valve seat 7 and acts on the head through the throttle hole 9. When the pressing force based on the fluid pressure 4 exceeds the spring force of the pressure adjusting spring 13 described above, the valve body 12 is opened and separated from the valve seat 7. In this disengaged state, the pressure fluid in the control passage 4 flows through the discharge passage 5 through the passage 11, the valve seat 7, the middle diameter portion 20C, etc., and is discharged to the tank T. Accordingly, the fluid pressure in the control passage 4 decreases. Thus, the maximum pressure corresponding to the spring force of the pressure regulating spring 13 maintained at the initial set value is set.

  In this state, when a predetermined current is applied to the coil 32 of the electromagnetic device 21, an acting force is generated in which the movable iron core 34 is attracted to the fixed iron core 33, and the pilot valve body 39 is seated on the pilot valve seat 25 by this acting force. Pilot pressure increases. For this reason, the piston 14 is separated from the stopper portion 2E by the shoulder portion 14C to the equilibrium position of the pressing force based on the increased pilot pressure and the spring force of the pressure adjusting spring 13 and the spring force of the return spring 16. It moves to the direction away from, and the spring force of the pressure regulation spring 13 is decreased. Therefore, the valve body 12 sets the fluid pressure in the control passage 4 by decreasing the spring force of the pressure regulating spring 13 pressed against the valve seat 7.

  Further, when the energization current to the coil 32 of the electromagnetic device 21 is increased by a predetermined current or more, the pilot pressure increases according to the increase in the energization current. Therefore, the piston 14 moves to a balance position between the pressing force based on the pilot pressure and the spring force of the pressure adjusting spring 13 and the spring force of the return spring 16 in a direction further away from the valve body 12 in accordance with the increase of the pilot pressure. It moves against the spring force of the return spring 16, and the spring force of the pressure regulating spring 13 is reduced according to the increase of the energization current. Accordingly, the fluid pressure in the control passage 4 is set to be reduced to a pressure corresponding to the spring force of the pressure regulating spring 13 that decreases as the energization current increases as the energization current to the coil 32 of the electromagnetic device 21 increases. .

  In such an operation, the pressure fluid in the control passage 4 is discharged to the tank T through the discharge passage 5 communicating with the middle diameter portion 2C of the valve hole 2 by the opening operation of the valve body 12, and via the pilot valve 18 including the electromagnetic device 21. Without flowing through the discharge passage 5 to the low pressure side. For this reason, even when the control passage 4, the valve hole 2, the valve body 12, the discharge passage 5 and the like are enlarged, it is not necessary to enlarge the pilot valve 18 including the electromagnetic device 21. Therefore, it is possible to control the fluid pressure in the control passage in the above-described intended control mode while maintaining the downsizing of the pilot valve 18 including the electromagnetic device 21.

  In this embodiment, the electromagnetic device 21 of the pilot valve 18 is an electromagnetic device in which the acting force by which the movable iron core 34 is attracted to the fixed iron core 33 increases as the energization current to the coil 32 increases. The valve 18 includes a pilot valve body 39 and a pilot valve seat 25 that increase the pilot pressure in response to an increase in the acting force of the electromagnetic device 21. Further, the piston 14 acts on the piston 14 in a direction to reduce the spring force of the pressure adjusting spring 13, and the spring force of the return spring 16 accommodated in the valve hole 2 acts against the pilot pressure. Has been. For this reason, it is possible to constitute the electromagnetic proportional pressure control valve using the general-purpose electromagnetic device 21 in which the pilot pressure increases as the energization current to the coil 32 increases.

  In the above-described embodiment, the electromagnetic proportional pressure control valve is configured using the general-purpose electromagnetic device 21 in which the pilot pressure increases in accordance with the increase in the energization current to the coil 32. However, instead of the electromagnetic device 21 described above, It is also possible to configure the electromagnetic proportional pressure control valve using an electromagnetic device in which the pilot pressure decreases in accordance with an increase in the energization current to the coil. In this case, the return spring 16 of the embodiment and the hole penetrating in the axial direction of the piston 14 are eliminated, and the chamber in which the return spring 16 is accommodated is used as a pilot chamber in the pilot chamber. It is necessary to connect the pilot passage 28 in communication and to connect the pilot chamber 15 of the above embodiment to the tank T.

  By making the control passage 4 of the above embodiment a pilot passage of a main valve (not shown), the electromagnetic proportional pressure control valve of the present invention can be used as a pilot operated relief valve, a pilot operated pressure reducing valve, a pilot operated sequence valve, etc. It can also be applied as a pilot valve of a valve.

It is a longitudinal cross-sectional view which shows one Embodiment of the electromagnetic proportional pressure control valve by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Valve body 2 Valve hole 4 Control passage 5 Discharge passage 7 Valve seat 12 Valve body 13 Pressure regulating spring 14 Piston 16 Return spring 18 Pilot valve 21 Electromagnetic device 32 Coil 33 Fixed iron core 34 Movable iron core 25 Pilot valve seat 39 Pilot valve body

Claims (2)

  The valve hole of the valve body is connected to and communicated with a control passage through which the pressure fluid flows at a required axial interval and a discharge passage through which the working fluid flows to the low pressure side. A valve seat is formed between the discharge passage communicating portion, and a valve body that is seated on and separated from the valve seat is movably accommodated in the valve hole. The spring force of the accommodated pressure regulating spring acts in the seating direction, the fluid pressure in the control passage acts in the separation direction against the spring force of the pressure regulating spring, and the spring force of the pressure regulating spring is reduced. An increasing / decreasing piston is movably accommodated in the valve hole, and a pilot pressure corresponding to the operating force of an electromagnetic device provided in the pilot valve acts on the piston, and the piston moves according to the pilot pressure. And the spring force of the pressure adjusting spring is increased or decreased. Electromagnetic proportional pressure control valve to. 2. The electromagnetic proportional pressure control valve according to claim 1, wherein the electromagnetic device is an electromagnetic device in which an acting force of the movable iron core attracted to the fixed iron core increases in accordance with an increase in an energization current to the coil, and the pilot valve Comprises a pilot valve body and a pilot valve seat that increase the pilot pressure in response to an increase in the acting force of the electromagnetic device, and the pilot pressure is applied to the piston in a direction in which the spring force of the pressure regulating spring decreases. And an electromagnetic proportional pressure control valve configured so that the spring force of the return spring accommodated in the valve hole acts against the pilot pressure.

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